BOSTON (AP) — This is the weekend Boston is beginning its new extended bus and subway service.

Beginning Friday night, the MBTA says its subway and 15 major bus routes will run until around 3 a.m. The service will operate at the same stations and stops it does on weekdays, and fares will be the same.

The last Red, Orange, Blue and Green Line trains will depart downtown stations at about 2:30 a.m. on Friday and Saturday nights.

The extended late night service will operate approximately every 15-20 minutes, with more frequent service in the core of the system.

The new service will not charge commuters more, but will cost the city about $17 million with the help of sponsors such as Dunkin-Donuts, the Red Sox and the Massachusetts Restaurant Association.